import java.util.Scanner;

public class Main {
    public static double TextMessage(int x, int[] array) {
        double money = 0.0;
        for (int i = 0; i < array.length; i++) {
        }
        return money;
    }

    public static void main(String[] args) {
        Scanner num = new Scanner(System.in);
        int n = num.nextInt();
        int[] arr = new int[n];
        for (int i = 0; i < arr.length; i++) {
            arr[i] = num.nextInt();
        }
        double cost = TextMessage(n, arr);
        System.out.println(cost);
    }
}